Recess plate are known in the art, inter alia from DE 103 04 004. Furthermore, JVK Filtration Systems GmbH/Germany, supplier of recess plates, is known to have combined two base elements of size 1200×1200 mm and installed the same to a large filter device.
The known recess plates, in particular made of polypropylene, allow for building a filter device that exceeds production dimensions of a common injection molding process, and the dimensions of common transportation facilities. In the known recess plates, the extension that is connected to the base element is a second base element, both base elements comprising respective recesses and fluid ducts for piping the suspension into the respective filtrate chambers, and the filtrate out of the same. The known recess plates use support frames for supporting the base elements and keeping the base elements in position.
Further commonly known recess plates comprise fluid pipes for several fluids, in particular for the suspension, for the filtrate, for a washing liquid, for a drying gas, and for a squeezing fluid, the fluid pipes distributing the respective fluid along a narrow edge of the base element to several inlets into the respective filter chamber, or collecting it from several outlets out of the filter chamber. Within the known recess plates, these fluid pipes either are formed inside the base element, or inside the extension, or externally flanged to the recess plate.
Where overall dimensions of a filter device are commonly restricted, both the support frames, the respective connecting device between the base element and the extension, and the fluid pipes of the known recess plates require space, thus reducing the potential remaining effective filter surface of the recess plate.